Adjustable knife for roughage mills



Oct. 10, 1933. w. HOLLAND-LETZ ADJUSTABLE KNIFE FOR ROUGHAGE MILLS Filed May 16, 1950 INVENTOR. i/iiizamffiflanoi zieiz A TTORNEY.

Patented Oct. 10, 1933 .UNITED STATES ADJUSTABLE KNIFE FOR ROUGHAGE Y MILLS William Holland-Letz, Crown Point, Ind; as-

signor toThe Letz Manufacturing Company,

a corporation of Indiana,

Application May 16, 1930. Serial No. 452,896

3 Claims.

. The present invention is directed generally to roughage mill and more. particularly to an arrangement or construction for adjusting the knife in the cutter head of the mill.

The primary object of the present invention is to provide a novel and improved adjustable knife holder for a knife head by means of which a knife having two oppositely arranged cutting edges may be adjusted with respect to the cutter head.

A further object of the invention is to provide an adjustable knife holderiin which a knife having 'tWo cutting edges of relatively thin piece of knife steel may be used.

A further object of the invention is to provide an adjustable knife holding device for cutter head used in connection with a roughage millby means of which a relatively thin knife blade with two edges of the knife may be used before resharpening of the knife is necessary. The present invention also permits the knife to be properly adjusted with respect to the cutter bar of the mill so: that as the edge of the knife wears by reason of grind- 60 ing, the knife may be advanced to its proper position with respect to its co-acting cutter bar of the mill. l In illustrating the preferred form of my invention I have shown the same in connection with a 65 fragmentary portion of a cutter head casting. In the drawing is shown an arm 10 which is one of the spider arms of the revolving cutter head casting. The outer ends of each of these arms 10 are provided with an angularly disposed L-shaped 70 portion 11, which in effect form a seat 12 for the cuttingedges may be supported and lockedthere in and in which the cutting edge of the knife therein may be adjusted with relation to the cutter without ruining the unused edge of the cutter knife. I

These and other objects are accomplished by providing a construction and an'arrangement of the various parts in.a manner hereinafter described and particularly pointed out in the appended claims.

Referring to the drawing:

i Fig. 1 is a side elevational view of a fragmentary portion of an arm of acutter head casting for roughage mill showing the preferred form of my improved adjustable knife holder mounted thereon; I

' v Fig. 2 is a top plan view of the same;

' Fig. '3 is a cross sectional view taken on the line 33 in Fig. 2;

Fig. 4 is a top plan view of a modified form of an improved form of adjustable knife holder for roughage mill;

Fig. 5 is a cross sectional view taken on the line 5-5 in Fig. 4;

Fig. 6 is another modified form of an improved form of adjustable knife holder;

Fig. 7 is a cross sectional view taken on the line 77 inFig. 6;

Fig. 8 is a longitudinal cross-sectional view of the knife plate shown in Fig. 7, and

Fig. 9 is a cross sectional view of another modification of a clamp type holder for a cutter head.

The present invention is specifically directed to the construction of a novel form of knife holder which permits the use of a relatively thin blade of a knife made from specially selected steel and also makes it possible to use adouble cutting edge on the opposite edges of the knife, so that both knife and knife plate hereinafter described. The rear end of this L-shaped portion'll is provided withtwo transversely extending threaded apertures 13 for the reception of threaded set screws '14. These set screws are locked in various positions of adjustment by a lock nut 15. Extending through the other partof the L-shaped portion 11 of the arm 10 are slotted apertures 16'. Mounted on the seat 12 of the L-shaped portion 11 is a 89 cutter'knife 1'? which is. preferably made of relatively thin specially selected steel. This knife 17 isprovided with two cutting edges as shown at 18 and 19. Mounted on top of the knife 1'7 is a knife plate 20. The plate 20 andthe knife 17 are provided with registering apertures 21 and 22 respectively. Extending through the apertures;2l and 22 of the plate 20 and knife 17,,respectively, and extending through the slotted apertures 16 is a bolt 23'for securing the plate 20 and knife 17 to the arm 10 of the cutter head casting. The rear end or edge of the plate 20 is located in the path of the set screws 14 so as to be contacted therewith,

as shown at 24, for relatively adjusting the cutter edge 18 of the knife with respect to the cutter bar on the mill.-

From the above description it will be readily seen by loosening the nuts on the bolts 23 that the set screws 14 may be adjusted after loosening the lock nuts 15 so that the cutting edge 18 may be 10 relatively adjusted with respect to the arm 10 of the cutter head casting, after which the bolts 23 may then be secured for digidly securing the knife to the cutter head.

In the modified form shown in Figs. 4 and 5, the knife seat 11 of the arm 10 is provided with a round aperture 25. The knife 17 in this instance is provided with slotted apertures as shown at 26, and the plate 20' is also provided with registering slotted apertures 27. The slotted apertures '19 26 in the knife 17 are relatively longer than the slotted apertures 27 in the plate The forward edge of the plate 20 is provided with depressed or off-set portions as shown at 28. These depressed or off-set portions 28 are in transverse alignment with theslotted apertures 27 in the plate 20 and are adapted to engage .the forward portion of the slotted apertures 26 in the knife 1'7 Obviously when the bolts 23 are as shown at 2 9. loosened and the set screws 14 adjusted, the plate" 20 will be moved and in turn will move the knife 17' for adjusting the cutter edge 18 of the knife with respect to its seat on the cutter head casting.

Another modified form ofmy improved knife holder is disclosed in Fi s'fi; '1' and 8.2fm this form, the knife in addition to being provided with the slotted apertures 26, is also providedwith two centrally located round apertures 30. These round apertures 30 are adapted to receive in engagement therewith, dowel pins 31 secured to the plate 32'. plate 32 is also provided with slottedapertures' 33, which are adapted. to register with the slotted apertures 26' in the knife 17' for receiving the securing bclts 23. Obviously a when the bolts'23'are loosened, the setscrews 14 may be turnedforadjusting the plate 32 which, on

account: of the dowel pins 31' engaging the. knife blade 17", the knife may be adjusted forproperly positioning thefeutting: edge with respect to coacting cutter baron the roughagemill';

In the last modification of my invention. SHOWIL in: Figl'Q' I have provided a clamp-like holder which is preferabh formed as anintegral part the arm. ll]; of the cutter castingr The knife hold.-

er in this form comprises two spaced apart 'flat portions 34'and 35 which are: preferably formed as" an integral part of the. armrlo' of the cutter head casting; These two flat portions 3-4; and snare so spaced apart asto form in effect a recess 36- there-- between; folr'the reception ofa plate: 37 and. a knife blade 38. The plate 37 is provided slotted apertures' as shown-at.39 which register with woundapertures iolgand il formed on the,

bcttom'portion 34 and 35 respectively forre'ceiv-v v ,3 ing the securing bolts 23. The f orwardp'ortion of the plate: 'ispifovided with" two doweltp'ins which are adapted to be seated i zn-the round aper tures: 5. formed tithe knife blade 38;. The: rear edge time holder portions' 3-4 and 35 are provided with: threadedapertures 46 for the reception of the set screws-47, The forward edge of the set screws e'lfare adapted to engage the rear edge of the plate 37, as shown at 48 for adjusting the cutting ed'geof the knife 38 respect to the cutter headcasti'ngf Obviously when the dc? sired position of the cutter edge has beenattained the clamping bolts 23 may be tightened thereby clamping the two portions 34 and 35 together for rigidly securing the knife in the cutter head.

7 From the above description it Will readily be seen that I have provided a simple and'eificient means inseve'ral different-forms of a knife holder for a cutter head by means of which arelatively thin knife blade having oppositely disposed double cutting edges may be secured therein and adjusted, with respect to the holder thereby extending the life of the knife before a resharpen- 'ing of the same is necessary. This construction also permits. the adjustment of the knife with re-,

spect to the: knife 'holder without ruining the sharp cutting edge that is not being used.

Whileinithe above specification I'have disclosed one" form of my invention, it will of course "be understood thatfother forms and additional modifications may' be made without departing from the spirit-and 'scope' of my inyention as it is expressedi-nthe following claims.

I claim is my invention-and desire to; secure by Letters Patent-is: V f

1 l; A knife-holder for a cutter headfconiprising acutter head casting, "a relativelythin knife secured to s'aid casting, said knife having opposites 1y disposedcutting edges, a plate mounted on said knife, securing means for securing said plate" and knife to said casting, a set screw mounted on. said casting and engage'able with one of theedges of said plate for adjusting said-knife with respect.

to said casting. s V

j 2. A; knife holder for; a cutter head comprising a cutter head casting, a knife securedt'o said casting, a plate mountedon said knife, bolts extend? ing through registering apertures in said plate,

kni-f'eand cutter head casting, for" securing said plate and knife to saidcutter head, and set screws mounted in threaded engagement withsaizigcaste ingand engageab-le with said plate" for adjusting the cutting edge of said knifewith respect to said casting;

3. n; knife holder for a cutter hea-d comp rising my a cutter head casting; a relatively thin, knife HES mounted on said casting, said knife havingthe ran 

